Polyarylene resins, such as those disclosed in U.S. Pat. No. 5,965,679 (Godschalx et al.) are low dielectric constant materials suitable for use as insulating films in semiconductor devices, especially integrated circuits. Such polyarylene compounds are prepared by reacting polyfunctional compounds having two or more cyclopentadienone groups with polyfunctional compounds having two or more aromatic acetylene groups, at least some of the polyfunctional compounds having three or more reactive groups. Certain single component reactive monomers which contained one cyclopentadienone group together with two aromatic acetylene groups, specifically 3,4-bis(3-(phenylethynyl)phenyl)-2,5-dicyclopentadienone and 3,4-bis(4-(phenylethynyl)phenyl)-2,5-dicyclopentadienone, and polymers made from such monomers were also disclosed in the foregoing reference. Typically, these materials are B-staged in solvent solution and then spin coated onto a substrate followed by a hotplate baking step and a subsequent curing (vitrification) to 400-450° C. in an oven to complete the cure.
In U.S. Pat. No. 6,359,091, it was taught that it may be desirable to adjust the modulus of polymers as taught in Godschalx et al., by adjusting the ratio of the reactants in Godschalx or by adding other reactive species to the monomers or to the partially polymerized product of Godschalx. U.S. Pat. No. 6,172,128 teaches aromatic polymers containing cyclopentadienone groups that may react with aromatic polymers containing phenylacetylene groups to provide branched or cross-linked polymers. U.S. Pat. No. 6,156,812 shows polymers which contain both cyclopentadienone groups and phenyl acetylene groups in the backbone of the polymer. In WO00/31183, cross-linkable compositions comprising a cross-linkable hydrocarbon-containing matrix precursor and a pore forming substance (poragen) which are curable to form low dielectric constant insulating layers for semiconductor devices were disclosed. Generally, the foregoing disclosure taught the formation of improved (lower) dielectric constant insulating films by partially curing the precursor to form a matrix containing occlusions of the poragen and then removing the pore generating material to form voids or pores in the matrix material.
Although the foregoing advances have led to improvements in dielectric constant of the resulting film, additional improvements in film properties are desired by the industry. In particular, curable compositions capable of providing enhanced processability, improved solubility, and better substrate wet out are still desired. In addition, compositions having improved physical properties, especially as measured by the flexural storage modulus of the partially cured matrix, are also sought.